REVENUE RECOGNITION - Adjustments to Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	$ 141,285	$ 141,500
Accounts Receivable, net	62,212
Accumulated Deficit	(15,000)		$ (14,534)
Difference Between Revenue Guidance In Effect before And After Topic 606, Adjustment For Implicit Price Concession Of Bad Debt Expense | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	3,463
Difference Between Revenue Guidance In Effect before And After Topic 606, Adjustment For Implementation | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	(256)
Accumulated Deficit	256
Difference Between Revenue Guidance In Effect before And After Topic 606, Tax Adjustment | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accumulated Deficit	(82)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	3,207
Accounts Receivable, net	(256)
Accumulated Deficit	174
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	144,492
Accounts Receivable, net	61,956
Accumulated Deficit	$ (14,826)